Adding and subtracting mechanism



Dec. 4, 1945. H. H. KEEN ET AL 2,390,441

ADDING AND SUBTRACTING MECHANISM Filed Aug. 9, 1940 6 Sheets-Sheet 1 Dec. 4, 1945. H. H. KEEN ETAL ADDING AND SUBTRACTINQMECHANISM Filed Aug. 9, 1940 6 Sheets-Sheet 2 I III!!! I vii I If.

INVEN HS Dec. 4, 1945. H. H. KEEN ET AL ADDING AND SUBTRACTING MECHANISM Filed Aug. 9, 1940 6 Sheets-Sheet 3 I4O A INVENTORS Dec. 4, 1945. v v H. H. KEEN ETAL 2,390,441

ADDING AND SUBTRACTING MECHANISM Filed Aug. 9, 1940 6 Sheets-Sheet 4 Dec. 4, 1945. H. H. KEEN ET AL 2,390,441

ADDING AND SUBTRACTING MECHANISM Filed Aug. 9, 1940 6 Sheets-Sheet 5 Dec. 4, 1945. H H. KEEN ET AL 2,390,441

ADDING AND SUBTRACTING MECHANISM Filed Aug. 9, 1940 6 Sheets-Sheet 6 KW j; 6 I

Patented Dec. 4, 1945 UNITED STATES PATENT "ornce ADDING AND SUB'IBACI'ING MECHANISM Hamid Hall Keen and Thomas Oliver Wright, Letchworth, England, assignors to International Business Machines Corporation, New York,

- N. Y., a corporation of New York Application August .9, 1940, Serial No. 351,948 In Great Britain August 15, 1939 4 6 Claims. (Cl. 235-613) each denomination is turned in one direction for adding the value of a digit to the total in the totalizer and in the other direction for subtracting the value of a digit from the total in the totalizer, and a register member turns in one direction when the entry member is turned to add and in the other direction when the entry memher is turned to subtract whereb entries may be made into all denominations simultaneously and transfer mechanism for each denomination operates, after passage by the register member through a predetermined position when turning in the direction foradding, to add unity to the next higher denomination, when there is a higher denomination but, in the case of the highest denomination, to add unity to the lowest denomination, and operates, after passage by the rot ster member through the said position when tuming in the direction for subtracting, to subtract unity from the next higher denomination when there is a higher denomination but, in the case of the highest denomination, to subtract unity from the lowest denomination.

The word digit", which is normally used to mean one of the numbers to 9, will be deemed to include any number up to but not including the base of the system of notation used. Thus, in the duo-decimal system, the numbers 10 and 11 are deemed to be digits.

One form of totalizer according to this invention, applicable to a statistical machine, will be described with reference to the accompanying drawings, in which:

Figure 1 is a side view of a totalizer, of which one denomination is visible.

Figure 2 is a section of the sun and'planet mechanism with transfer cams and read-out commutator. a

Figure 3 is a section thereof on the line of Figure 2, with parts broken away.

Figure 4 is a vertical section on line BB 0! Figure 1, showing the reversible gearing and two totalizer denomination support plates.

Figures 5 and 6 are sections showing elements of the reversible gearing, on the lines CC and DD respectively of Figure 4.

Figure 7 is a circuit diagramshowing the con nections of the totalizer to the circuits of a tabulating machine, I V

Figure 8 is a cam timing diagram. Figure!) is a back view of a read-out commutator.

Figure 10 is a circuit diagram showing the cir-' cuits for selecting the true total.

Figure 11 is an alternative form of part of the circuits of Figure 10.

Figure 12 is a view similar to that of Figure showing an alternative form suitable for duodecimal notation.

Figure 13 is a circuit diagram showing a cirarts of Figure 1, and

Figure 15 is a circuit diagram for the modification shown in Figure 14.

Referring to Figure l, the parts for each denomination of the totalizer are carried on a plate I, supported on side members 2. The parts are similar for each denomination, and two plates l for two denominations are shown in .Figure 4. The main driving shaft 4 and the intermediate driving shaft 5 extend through all denominations of the totalizer and are carried in end plates 6, attached to the side members 2 by brackets I.

In Figure 4, the shaft 5 is shown in dotted lines as it is behind the line of the section. The shaft 5 is driven by the shaft 4 by the gear wheels 31 and 9.

The shaft 4 turns constantly counter-clockwise as seen in Figure 1. Gear wheels 31 and 9 are ele ments of the reversible gearing to be described, such that the shaft 5 is turned in one direction for adding and the other for subtracting. These directions are indicated for this and other shafts by double-ended arrows marked A and S.

The elements, in one denomination of the totalizer, shown to the right of the plate I in Figure 2 comprise a driven member, a sun and planet gearing, and parts of a re ister member. The driven member or gear wheel I is driven by the shaft 5 through the gear wheel 9 and idler gear wheel l0 turning on a stud II on the plate I. A sun wheel I! is attached to the wheel I and engages a pair of planet wheels I: on shafts l4 in a cage IS. The wheels 8 and i2 and the cage Ii turn on a tubular stud ll fixed to the plate I. The right-hand ends (Figure 2) of the shafts l4 carryplanet wheels II which eng ge a wheel it fixed to the shaft 19 which turns in the tubular stud l6 and passes through the plate I to carry the read-out commutator to the left of the plate. Also fixed .to the shaft l9 are a locking plate 20 and two transfer cams 2| and 22 for adding and subtracting respectively. The cage l has formed on it a locking plate'23. The cam 2| is broken away in Figure 1 to show the cam 22 below it and this also is broken away to show the locking plate below it. The parts l8v to 22 and the read-out commutator constitute the register member, because they all turn with the shaft 19 to register the amounts entered into the denomination of the totalizer.

The locking plate 20 and the cage locking plate 23 are locked alternatively by the two arms 24 and 25 respectively of a four-armed lever 24, 25, 26, 21, pivoted on a stud 28 on the plate I. The arm 24 is shown pivoted independently on the stud 28 and is held in-a fixed position relatively to the other arms by the spring 29 and the lug 39 which is bent downwards to engage the arm 21. This construction is for safety and, in operation, the arm 24 may be regarded as integral with the other arms of the lever. The lever is turned clockwise into theposition shown by the cams 3| and 32 on the shaft 4 engaging the arm 26, and it is held in the position shown by the armature 33 of the electromagnet 34 engaging the arm 21. The spring 35 tends to .turn the lever 242l counter-clockwise and the spring 36 tends to hold the armature 33 away from the -magnet 34. y

In the position of the parts shown, the arm 24 is looking the register member of the totalizer gear by engaging the locking plate 28 and, the wheel 8 being constantly turned, the cage l5 and planet wheels turn idly. Thus, the wheel l2 fixed to the wheel 8 turns the planet wheels I3, and therefore the planet wheels l1, and these roll around the wheel I8 which is fixed to the locked wheel 20, carrying the cage I5 with them. If now the magnet 34 be energised, its armature disengages from the arm 21,,and the lever 24-21 is turned counter-clockwise by the spring 35, so that the arm 24 releases the locking plate 20 and, simultaneously, the arm 25 engages the locking plate 23, to hold the cage I5 stationary. Assuming the wheel 8 to be turning counter-clockwise for adding, the planet wheels l3 will be turned clockwise by the wheel l2, and the planet wheels II will turn the wheel l8, and therefore the whole register member counter-clockwise. The-v ratios of the wheel teeth are such that the register member turns one-third of a revolution for one revolution of the wheel 8, and the wheel 8 is turned sixteen revolutions for ten revolutions of the shaft 4. When the locking plate 29 is locked, the cage l5 with looking plate 23 makes half a revolution per revolution of .the wheel 8. The

reason for these ratios is that the register member shown is designed for decimal notation and for use with a statistical machine of the Hollerith type which operates on a particular cycle having 16 cyclic intervals customarily indicated. by .the following characters, which indicate points separating the intervals: 9, 8, '7, 6, 5, 4, 3, 2, 1, 0, X, Y, Z, E, F, G. In this cycle, the value of a digit, say 6, is represented by the six intervals between the points 6 and 0, while the intervals between 0 and 9 are allocated to transfers from one denomination to another and to resetting. The

by one-thirtieth of a revolution of the register member. The locking plate 20 on the register member has notches, and therefore the interval between adjacent notches represents a unit digit. The register member is made to register 0 to 9 three times in a revolution for convenience in construction. When looking plate 23 is released, it makes half a turn for one turn of gear 8, as previously explained. Since gear 8 makes one tenth of a revolution in a cyclic interval, the plate 23, in such interval, will mak one-twentieth of a revolution. According, plate 23 is provided with 20 notches so that it may be arrested at any twentieth part of its revolution during a chosen cyclic interval.

The operation of entering into the totalizer the value of a digit, say 6, resulting from the operation of the statistical machine is as follows: At the point 6 in the cycle, the magnet 34 is energised and the related register member begins to turn; at the point 0, the cam 3| strikes the arm 25, thus locking the register member and resetting the lever 242l. In the/ interval 6 to 0 therefore the register member has been turned through an angle comprising six notches of the plate 20 and representing the digit 6. The operation is the same if the digit is to be subtracted,

except that the register member turn in the opposite direction.

The transfer mechanism will now be described. It is of the known type in which all transfer between the diiferent denominations are made simultaneously. Thus, if the totalizer stood at 19999 and l were added, the four transfers required to give the result 20000 are made simultaneously. This is effected by causing the parts in a denomination to take up a "long transfer position, when, in adding, 9 is registered in that denomination (assuming the totalizer to be for decimal notation) If a transfer is effected from one denomination by adding 1 to the next higher denomination when the parts. of this latter are in long transfer position, a transfer is also effected by adding 1 to the second higher denom- 5 ination.

This type of simultaneous transfer may be effected mechanically or electrically. In the totalizershown it is effected partly mechanically and partly electrically. Considering first the transfer mechanism operable during adding, a transfer pawl 38 on an arm 39 pivoted to the plate I at 40, engages the adding transfer cam 21. This has a notch 4| constituting the long transfer step, preceding a projection 42, constituting the ordinary or short transfer step. The pawl 38 engages the notch 4|, as shown in Figure 1, when the register member stands at 9, and is raised by the Y Thereby the arm 39 is held in its raised position whenever the register member passes from 9 to 0.

Above the arm 39, a contact arm 45 is pivoted at 48 to an insulating block 41 and is urged downwards by a spring 48. The contact blade 49 of the arm is shown in its lowest position making contact with the contact piece 50, and it can occupy an upper position, shown in dotted lines,

slmft 4 makes one revolution per cycle, and a unit digit is therefore represented by one-sixteenth of a revolution of the shaft, and therefore by one-tenth of a revolution of the wheel 8, and

in which it makes contact with the contact piece 5|. It can also occupy an intermediate position, also shown in dotted lines, in which no contact is made. The contact arm 45 is operated by the arm 39 by-means of an interposer 52 on the lated from contact arm 45 and for this purpose,

arm 58 may be made of insulating material. It will be clear,,further, that contacts 58 and 5i 7 are carried by support plate i through insulation.

The arm 55 remains in the position shown during adding operations. When'the pawl 88 is'in the notch 4|, the contact blade 48 is allowed to rest on the contact 58. The parts arethen in long transfer position, the register member being at 9. In passing to 0, when the arm 88 is held in its raised position, the contact blade 48 is pressed by the interposer 52 and arm 58 against the upper contact ii. The parts are then in short transfer position,:to control additive transfer of 1 to. the next higher denomination. When the pawl 88 is engagingthe rim of the cam 2i the contact blade 48 is in its intermediate position, in which no contact is made. It may be noted that there are three notches 4i in. the cam .2l, in positions corresponding to the three 9 positions, each match preceding a projection 42.

Before describing how the transfers are completed as a result of contacts with the pieces 58 and 5!, there will be described the devices for making the same contacts at the appropriate times during a subtracting operation.

In subtracting, the transfer must be eifected when the register member passes from .0 to 9,

and the long transfer position must be taken up when the register member is at 0. For this purposer 52 when this is in' the position shown for adding. By reason of the notch 58, the arin 51 is raised and lowered by the projections 5| and notches 88 without striking the interposer, and is therefore ineffective. Now when the reversible gearing, which releasably drives the register members, is operated to change'from adding direction to subtracting direction, the arm 55 is moved to the right into the position shown in dotted lines, by means to be described later. Thereby the arm 58 is moved to bring the interposer 52 into the position shown in dotted lines in which it is clear of the notch 58 in the arm 51, but is over a similar notch 82 in the arm88. In this way the arm 51 is made effective to actuate the contact arm 45, while the arm becomes ineffective. Therefore, in subtracting; when the register member reaches 0, the pawl 58 drops into the notch 88, and allows the blade 48 to rest on the contact 58 to effect along transfer and, in passing from disc 88 and, loose on it, a disc support 84, with cam plate 85.

The support 84 carries a shaft 88 having, at one end, a gear wheel 81 engaging the gear wheel 82 and, at the other end, a gear wheel 58. The wheel 88 engages an idler wheel '88, pivoted on the support 84, which in turn engages a gear wheel 18 attached to the gear wheel 81 and loose on the shaft 4. The support 84 carries a pawl 1i pivoted to it at 12 which is adapted to enter a notch 18in the disc 88 under the tension of the spring 14. When the pawl 1i is in'the notch 18, the support 84 is locked to the disc 88 and shaft 4 and the gear wheels 81 and 88 are prevented from turning. The whole assembly therefore turns with the shaft 4 and carries with it the gear wheels," and 81. The parts are then turning in the direction for sub trizchting, indicated in-the drawings by arrows W Ila-II One end 15 of the pawl 1| projects beyond the edge of the support 84 and is adapted to be caught and held by the arm'18 (Figure 1). When so held, the pawl 1| is withdrawn from the notch '13 and it and the support 84 are held stationary. Then the wheel 82 fixed on the shaft 4 drives the wheel 18 through the gear wheels 51, 58 and 88, and the wheel 18, to which the wheel 31 is fixed, is turned in the opposite direction to that of the shaft 4, the parts turning in the direction for adding, as indicated by the arrows with A." The ratios of the teeth of the wheels 82, 81, 88 and 18 are such that the speed of the wheels 18 and 81 is the same as that of the shaft 4, but in the opposite direction.

The cam disc 85 has a depression 11 in which, when the support 64 is held stationary, the roller 18 on the arm 18 (Figure 1) rests. The arm 18 is fixed to a shaft 80pivoted in the end plates 8 and carries, at each denomination of the totalizer, an arm 8| adapted to engage the arm 82 of the lever arm 55 pivoted at 58. When the support 84 with cam disc 55 is stationary, that is to say in adding, the arm 18, 8| and 82 are in the positions shown in Figure l, and the arm 55 is in the position shown in full lines. When the support 84 turns, that is to say in subtracting, the arms 18 and 81 are turned counterclockwise as the depression 11 passes from under the roller 18, and thereby the arm 55 is moved .into the position shown in dotted lines. In this way, when the reversible gear is operated in the direction for subtracting, the arm 55 is moved to place the interposer 52 in the. position to make the subtraction transfer mechanism eiIective. The shaft 4 carries at eachdenomination a cam block 83, with two cams 8| and 82 for resettingthe lever 24, 25, 28, 21 and a, cam 84 for-striking the tail 85 of the arm 44 to unlatch the pawl arms 38 and 51. The timing of these cams will be described later.

The arm 15 is operated to release the pawl 15 and support 84 as follows: The arm is pivoted at 85 to a support 81 fixed on the end plate 6' and carries the armature 88 of an elec- I tromagnet 88. It i normally held in the posi- 00 tion shown by a spring 80. A latch 8| is pivoted to the arm 15 at 82 and forms with the arm a slot in which the projection 15 is retained. The

latch is normally held in the position shown by the spring 88. When the magnet 88 is energised,

55 the arm 18 is rocked clockwise to release the support 54 which then turns counterclockwise, as viewed in Fig. 1. When the magnet is .de-ener- 'gised the projection 15, on reaching the arm 18, depresses the latch 8| and is held by the end of the arm, the latch then springing back into the position shown.

The operation of the totalizer under'contibl I of record cards passed through a Hollerith tabulating machine will now be described with reference to Figures 7 and 8. Figure 7 shows only magnets 34 in each denomination, the circuit being completed from the supply line 96 to the line 96a, through the usual circuit breaker LCB and card lever contact LCL. The different denominations, of which three only are shown, are indicated by the letters U, T, and H, respectively signifying units, tens, and hundreds. The magnet 99 is normally not energised, so that the support 64 in the-reversible gearing is held stationary, and the gearing operates in the direction for adding. As already explained, when a digit, say 6, is read by the lower brushes, the

circuit is completed to energise the magnet 34 in the appropriate denomination, and the related register member starts turning. At the point in the cycle, the cam 3| causes the register member to stop turning, the value 6 having then been added. Forrapid operation, the cam 3| operates a little after 0, as shown in Figure 8, to allow for lag in operation of the magnet 34 and lever 24, 25, 26, 21. Suppose that the number previously registered by the totalizer was 166 and that a number 126 is added, then the unit register member will have moved to 2, and in passing from 9 to 0, the arm 39 in the units denomination will have been raised into latched position, in which the blade 49 makes contact with the contact piece to control a short carry. The tens register member will have moved to 8, and the hundreds register member to 2, and the blades 49 in those denominations will be in their intermediate positions, making no contact. A little after the point Y in the cycle, cam contact I21 completes the circuit through the transfer relay magnet 95, open the contacts 95a and closing the contacts 95b. A circuit is then completed from the line 96 through the LCL contacts, cam contacts I55, the'contact 5| in the units denomination, to blade 49, thence through the contacts 95b and magnet 34 in the tens denomination, to the line 96a. The tens denomination register member will then start to add but, after an interval suflicient to enable it to add 1, cam 32, a little after point Z, moves the lever arm 26 to stop the turning of the register member. Thereby the transfer from the units to the tens denomination is effected, and the register member will stand at 292. A little before the point F in the cycle, cam 34 strikes the arm 85 to release the transfer arm 39. Since the tens register member now stands at 9, its

transfer arm 39 will have allowed the blade register members, and the number registered will be 400.

When the number recorded on a card is to be subtracted, this is indicated on the card by a special designation hole at one of the points X or Y, and this hole is sensed by the upper brushes. The presence of such a hole causes a circuit to be completed through relay magnet 91 thereby closing contacts 91a and b. Since cam contact leased only during a single revolution of the shaft 4. As far as the circuits in Figure 7 are conis the same as that of adding it, but the subtracthe reversible gearing, to effect transfers at the appropriate points.

The total registered in the totalizer may be indicated in various ways, by appropriate devices fixed to theregister members. Thus, digit indicating wheels may be fixed to the shafts l9 on the left hand side of the plates I, as seen in Figure 2. These will indicate the correct total, within the capacity of the totalizer, or the balance of the amounts added and subtracted, provided that the total of the amounts subtracted does not exceed the total of the amounts added. If it does exceed the total of the amounts added, so that the total represents a negative amount, this total may be shown in three different ways. In the totalizer so far described, if, when the register members stood at 000, one were subtracted, the register members would show 999 which is the tens complement of 1. In many operations, of statistical machines negative numbers are conveniently expressed as nines complements, by which minus 1 is expressed as 998. The totalizer can be arranged to indicate the nines complement of a negative total by the provision of a transfer mechanism to the highest denomination, as shown in Figure 7 in the case of the hundreds denomination, connection being made by the wire I99 from the blade 49 to the units denomination, Then, in subtraction, if the hundreds register member passes from 0 to 9', digit 1 is subtracted from the units denomination and the subtraction, for instance of one from 000 would give the result 998, which is the nines complement. The third way is to show the total as a. true number, whether positive or negative. Thus the same number 001 would be "shown whether a unit were added or subtracted from 000, but an indication would be given .to show whether the number shown was positive or negative. This can be done by using for instance two indicating wheels on the register member in each denomination, the number indicated on one wheel being the nines complement of that on the other wheel, and by providing an auxiliary denomination for indicating P poses only. This 7 auxiliary denomination will then stand at 0 so long as the total in the totalizer is positive but will move to 9if an amount be subtracted greater than the positive total. One of the indicating wheels in each denomination will show a digit of the true positive total it the auxiliary denomicemed, the operation of subtracting thenumber tion transfer is made operable, under control of nation shows 0. and the other indicating wheel will show a digit of the true negative total if the auxiliary d shows 9.

Thecircuits oi'l'igure'lwilleflectthisifitbe assumed thatthetotaliaerhasunitsand tensdenominations only, the hundreds denomination serving as auxiliary denomination. Then when, in subtraction, the tens denomination panes from to 9, the auxiliary hundreds denomination, previouslyato.willmoveto9,andwilltransferone by subtracting it fromthe units denomination.

and the negative indicating wheel will show a true negative total. when, by addition, the tens denomination passes from 9 to 0, the auxiliary hundreds denominationwillmovebackto O and will transfer one by adding it to the units denomination, and the p sitive indicating wheel will show a true positive total.

Theiollowingexampleshqwstheoperatiomthe -Indiv True Wheels A. D. rating total Mu" negative When the totalizer is used in connection with statistical or other calculating machines, it is generally required that the amount registered should be printed. or should be transferred-into another totalizer in which calculations are effected on it. For this purpose the register member order shown is'provided with two read-out commutators. These are shown in section in Figure 2 and in place with the cover rings removed in Figure 9. The two commutators are similar and each consists of a ring of insulating material IOI, fixed to the plate I, in which are embedded ten contact pieces I02, extending over one-third of the circumference. The contact pieces are thus separated by an angular distance equal to that of the notches on the locking plate, 20. Opposite these contact pieces is a common contact strip I03 embedded in the ring "I, and

extending over half the circumference. Keyed to the shaft I9 of the register member is a metal bushing I04 carrying a ring of insulating material I in which three contact brushes I00 at 120 degrees apart are adapted to slide, These are pressed outwards against the contact pieces I 02 and strip I03 by a coiled spring I01, which serves also to connect the brushes together electrically. In rotating, therefore, as soon as one of the brushes, in passing over the ten contact pieces I02, has connected them successively to the common contact strip I03, through one of the other brushes, the succeeding brush connects them successively to the common contact strip.

In the circuit diagram Figure 10, showing eight denominations of a totalizer, the positive commutators are represented diagrammatically by the contact pieces I02 and the negative by the contact pieces I02n, and the common strips by the reference letters I03 and I03n respectively. Likewise, the brushes of the positive and negative commutators are distinguished as I05 and I 0611, as indicated for the denomination at the bottom of Fig. 10. As seen in this diagram, the contact pieces of the positive and negative commutators of a denomination are connected electrically so that contact piece 9 on one is connectedto9ontheother.8to8,7to7.andsoon. For simplicity of illustration, the wiring between the contact pieces of the positive and negative commutators of some of the denominations has 10 I00 and I001: are shown in juxtaposition to all their associated contact pieces only for the denomination shown at the bottom of this figure. It will be imderstood, however, that the wiring between the contact pieces of each pair of commutators and the strips I00 and I001; of each such pair are the same for each denomination. The contact pieces of the positive commutators of all denominations are connected to contacts I00 of an emitter Ill'by wires Ill. The emitter I00, with common strip III and brushes H2 is of the ordinary type used in Holleritn tabulating machines and serves to connect the supply line 00 successively to the contact pieces of all the commutator-s. The common strips I03 and I031: are connected respectively to contacts Allie to DlI3a and AIIlan to DIISan of the four relays AIIO to cm. Normally. contacts Allla to DI Isa are closed, thereby connecting the positive commutators to magnets Ill. Thus, if the lowermost denominations shown in Fig. 10 registered the positive value 5, a positive value readout circuit for this denominationwould be closed during operation of the emitter I 00 as the brush II2 reached the 5" contact I00, as follows: from line 00, via common emitterstrip III, brush I I2, 5 contact I00, connected wire 0, the "5" contact piece I02 of the said denomination, the brush I00, common strip I03, and, via the connected contacts DII3a, through the lowermost magnet Ill, to line 000. In a manner explained vlater, when a negative number stands in the 'totalizer containing the denomination, the associated one of the AIIIato DI Ila contacts is opened and the associated one of the AlIlan to DI an contacts is closed. The value represented in the negative commutator will then be read out. For example, if the lowermost denomination in Fig. 10 registers the negative value 3, a. negative value readout circuit through the related magnet Ill will extend from line 06 via the emitter I00, in 3 position, to the 3 contact piece I 02 of the denomination, thence via the connection to the 3" contact piece I021: of this denomination, brush I00n, strip I 0311, con

tacts DI I3an, and through the lowermost magnet I I 0 to the supply line 96a. The magnet IIO may be the magnet in a tabulating machine causing the digit registered in the denomination of the totalizer to be printed, or it may represent, for instance, the actuating magnet of a totalizer to which the readingof the denomination is transferred.

The circuit diagram in Figure 10 shows the manner in which the true total, whether positive or negative, registered by the totalizer is read out to the magnets I I0, and also shows the manner in which a plurality of denominations (eight being shown in the drawings) may be connected so as to form either a. single totalizer or a plurality of independent totalizers. In the drawings, the denominations are shown permanently connected in pairs, but divisible so that two totalizers of two and six denominations or four and four denominations can be formed, and the plug connections shown are for two totalizers of beenomittedinl 'ig. 10, and thecontactpiecesfour and four denominations. From this diagram it will be clear how any number of denominations may be connected so as to form any combinations or them into totalizers. when a SIa-SIb, as shown in Fig. 7, may be used for all the denominations. When, however, a number of denominations are to be capableof being combined together to form one, two or more totalizers, a plurality of reversible gearings, each with its related magnet 89 and relay 91-9'Ic- 91b, must be provided. In the arrangement shown in Figure 10, in which the denominations are permanently connected in pairs, reversible gearing andan associated magnet 89 with control relay is provided for the two denominations of each pair, and two wheels 9, one for each denomination, may be conveniently mounted on a sleeve on a fixed shaft, one of the wheels 9 being driven by the wheel 31. If it be desired that any one denomination be capable of being connected with any others to form a totalizer, each denomination must be provided with its own reversible gearing, controlled by a related magnet 89 and relay 91-91d-9Ib, and the wheels 9, one for each denomination, may be mounted on studs on the plates l. The entry magnets 34, transfer relays 95 with their contacts 950 and 95b and transfer contacts 49, 50 and 5| are shown as in Figure 7, but only the wires 94 leading to the lower brushes are shown, and the circuits for operating the reversing control ma nets 89 and associated relays 9|--9Ia--9Ib, with the upper brushes, are omitted, since circuits for each magnet 89 and associated relay are such as shown in Fig. 7. The four pairs of denominations are distinguished by the letters A, B, C, D. The connections shown give two independent totalizers, one of which may be called the AB totalizer. composed of pairs of denominations A and B, so arranged that the units and tens denominations of the totalizer AB are in pair A and the hundreds and thousands (TH) denominations are in pair B. The other totalizer may be called C-D, with pair of denominations so arranged that the units and tens denominations are in pair C and the hundreds and thousands denominations are in pair D. The wire III] which, in Figure-I connects the contact blade 49 of the highest denomination to the contact 95b of the lowest denomination, to transfer one, is divided. in Figure 10, by plug connections 5, and the connections shown join the contact 49 of the thousands denomination in B to the contact 95b units denomination in A, and the contact I! of the thousands denomination in D to the contact 95b of the units denomination in C. Plug connections H6 are also provided whereby the contact blade 49 of the highest denomination in each pair may be connected either to the wire I" or to the contact 85b in the first denomination in another pair.

There will now be described the manner in which selection is made between the positive and negative read-out commutators, so that the commutators which register the true total, positive or negative, are connected to the magnets I I4. Heretofore this selection has commonly been made by allocating one denomination of the totalizer to the function of selection, so that this denomination is not available as one of the adding or subtracting denominations. By the de- 70 tacts I25'a to relay 8'.

vices shown in Figure 10, selection is made while all denominations are available for adding or subtracting. This is possible because means are providedto store, in efiect, the sign of the 5 amount registered by the totalizer. In short,

considering the totalizer AB and the embodiment shown in Fig. 10, upon passage or the totalizer from a positive to anegative amount registration, a relay II! is energized and held until the totalizer returns to a positive amount registration. The relay H8 when in energized status enables the true figures of a negative amount to be read out and when in deenergized status enables the positive amount to be read out. Since means are provided to store, in ctfeet, the sign of the registered amount, the highest denomination of the totalizer may be used to receive any of the digits of the notation since it is unnecessary to resrict the positions 01' the highest denomination to the 9 and positions as indications of negative and positive amounts, respectively. A detailed description 01' the sign storing means and the means related thereto is given in succeeding portions of the specification. An any cycle in which the amount registeredis a totalizer is to be read out to energize magnets Ill, the emitter I09 completes negative value or positive value readout circuits, such as previously traced, depending on whether the amount in the totalizer is negative or positive. Whenthe registered amount in the totalizer AB is positive, the contacts Allia and Bllia will be closed and positive value readout circuits will be formed'to read out the registered amount. 0n the other hand, if the registered amount is negative, contacts AllSan and BH 31m will be closed and negative value readout circuits will be completed. Similarly, negative or positive value readout circuits will be completed for reading out'the totalizer CD depending upon whether contacts Clllan and Dlltan or Cilia and DI I3a are closed. The adjustment of these several contacts is controlled by their correspondingly lettered relays coils AI I3 to DI l3. By 45 plug connections 1, the four relay coils Al Ii,

BN3, CH3, and DII3 can be connected as desired to the two contacts H811 and II8a of the two relays H8 and 8'. With the plugging shown in Fig. 10, if contacts Il8a are closed, coils 50 AI I3 and BI I3 will be energized upon closure of cam contacts H9, and if contacts II8'a are closed, coils CI I3 and DI I3 will be similarly energized. Relays H8 and H8 are elements of a selection means for selecting either the positive 55 or negative commutators oi. totalizers to be read out. Two such selection means are required for the arrangement shown in Fig. ,10, each such selection means being under control of one of the totalizers AB and C--D. To provide for 60 the requisite control, by the totalizer AB of the selection means including relay 8, the highest denomination (TH) of this totalizer has its contact blade 49 connected by means including plugwires IIIi, I22, and In to the cam contacts designated I24 which lead via normally closed contacts l25a to relay H8. Similarly, the highest denomination oftotalizer C--D is connected by means including plugwire I20 to cam contacts I24 which lead via normally closed con- It may be mentioned that cam contacts I24 and I24 are commonly operated and timed.

Now so long as the register member of the highest denomination registers a true positive number, that is to say any number from 0000 to 9999, the contact blade II makes no contact with contact II, but 11', in subtraction, the number is decreased below 0000 to become negative, the highest denomination passes from to I and the contact IIII is made. Then a circuit is completed from line II through cam contacts III, contacts II-II oi the highest denomination of, say, totalizer A-B, plug connection III, camcontacts III, contacts II of relay III, which are normally closed, relay III to line IIa. Thereby relays AIIIand BIII are operated to close contacts AIlIan and BIIIan to make the negative commutators of totaliaer AF-B effective. This negative valueto a positive valueistobeeilected asaresultoialongcarrmtheseleetionmeanlan ticipatesthis result'byth'e'prepared III circuit through relay III will not be completed on the following cycle, because contacts II-II will no longer be made; Provision therefore is or III relay'magnet by way of one car'ry' contact andiollowinglongcarryemitacts. 'I'he I presentinventionisnotconcernedwith meanafor denotingthe'signofthebalancereadoutofa made to retain a circuit through relay III, as 101- lows: Relay III also clom contact lIIb, to'eatablish a circuit from line II, contacts IIIb, normally closed contacts IIIa, relays III and III to line IIa. Relay III' is not however energised until cam contacts III are opened, because it is shunted by the circuit through these contacts. When contacts III are opened, relay III becomes energized and closes its contacts III!) to connect contacts III through relay III to, line Ila. Thereby a circuit is prepared through relay III when contacts II-II are next made. So long as they are not madefithat is to say, so long as the totalizer does not pas back from 9 to 0-in its highest denomination, the circuit remains through relay III by way of its contacts "lb and contacts IIIa. When the totalizer does so pass back, contacts Il -II are made to complete the circuit through relay III, whereby its contacts III!) are first made and thencontacts IIIa broken. The circuit through relays III and III is then' maintained through contacts IIIb until cam contacts III open, when relay III is de-energised to make the positive commutators again effective. The parts are then again in normal position. In a similar manner, when the totalizer C--D passes from a positive to a negative value, the contacts I9-5I of the highest denomination in this totalizer close and when cam contacts III and III close. a circuit makes from line II via contacts III, II-il in the TH denomination of 0-D, wire IIII, plugwire III, cam contacts 'III', contacts III'a, and relay III to line IIa.

totaliaer. It is manifest, however, that each ot the magnets AIII to DI II may control'sign denoting means-in the same way-as magnet IIIof Kolm Patent 2,019,883 controls @81 printing meansorinthesamewayasthe'printingofan' asterisk is controlledin Peirce Patent 2,056,383.

For the circuit network shown in Fig. 10 where magnets AI II and BI II are plugged together for common operatiomonlyoneof these magnetsmay An alternative form of device for operating the 1 contacts I IIa and I IId is shown diagrammatically in Figure 11. In the alternative torm,'the contacts IIIa are operated by a cam III which is on the shaft of a ratchet wheel III with ratchet pawl III on the armature III of an electro magnet- III. The ratchet wheel III has twice as many teeth as the cam III has projections so that, when operated step by' step bythe magnet III,

.the contacts IIIa are alternatively closed and opened. The magnet III is arranged to be energized by a circuit which starts in the same way as the circuit for coil I II (Fig. 10) i. e., from line II via contacts III, the contacts II-II of the highest order of totalizer A-B. the plugwire III, line III. and to the plugwire III. The circuit is comthat cam contacts III are unnecessary here be-.

cause it is not required to maintain magnet III energized, whereas in the Fig. 10 form, the magnet I II must be held energized by means including a relay II5 which is shunted by contacts III and does not take effect until the latter contacts open, On the other hand, with the means shown in Fig. 11, the magnet III need be energized only momentarily to effect a step of movement of ratchet III and connected cam III. The cam III itself holds the contacts I III: in adjusted podtion until magnet III is again energized by a suctacts III and III and III have closed and ceeding closure of contacts IIII (occurring opened. If a totalizer registered, say, positive amount 9314 and in a cycle, 9382 were subtracted. the denominations would register, before the transfer period, 0032. The tens denomination upon a reverse movement of the highest order through the critical position) In a similar manner, the magnet III may be energized by a circuit which extends from line 96 (Fig. 10) via cam contransfer contacts II-5I would be closed and the tacts III, the contacts I9--II of the highest order made via the closed II-II contacts and the contacts 49-50 of the higher denominations. suming, for instance, that this example were applied to totalizer A-B, the circuit of relay III would make from line 96 via contacts III, contacts II-II of the tens denomination, in A,

of totalizer C--D, thence via wire III to plugwire III. The circuit will be completed, as shown in 1 Fig. 11, from plugwire III through magnet III, to line 96a, Energization of magnet III at- Astracts armature III; thereby rocking pawl III to effect a step of movement of the ratchet I II which is rigidly connected to cam III". Cam

- III operates contacts IIIa, the function ofwhich is the same as that of the contacts IIIa thence via a plugwire III, contacts I95I of the in Fig. 10. Consequently, referring to the A-B totaliner, starting from a positive total, the circuit of magnet :32 is completed by closing of contacts "-49 when the total becomes negative, and the cam I2! is then arranged to close the contacts Illa to connect the negative commutators in circuit. When the contacts "-49 are next closed, on the total becoming positive, the cam I2! is actuated to open the contacts Illa to connect the positive commutators in circuit.

As explained previously, each denomination of a totalizer will have means for manifesting a positive balance and means for manifesting a negative balance. The positive balance manifesting means will manifest a digit of the true positive total, and the negative. means will manifest a digit of the true negative total. The digits of the two manifesting-devices simultaneously at index positions always add up to 9, as explained before. Thus,in Fig. 10, where the manifesting means are negative and positive readout commutators, when a brush "it of the positive commutator is on the spot, the brush I06 oi the companion negative commutator is on the 9 spot. Now, assume the totalizer is at 0 positive starting position and has four denominations. When all four denominations are to receive entries of any of the digits of the notation, the capacity of the totalizer is 9999, negative or positive. Assume that plus 9999 is entered. None of the register members will pass from 9 to 0 and, hence, carries will not be efiected. The positive commutators will manifest 9999 and such total may be read out therefrom during a total taking operation. Assume, instead, that minus 9999 is to be entered. with the totalizer in zero positive start position, the brushes of the negative .commutators will be initially on the 9 spots of the four negative commutatorsof the totalizer. The entry of negative 9999 causes the register members to move in a sub-- tract direction through nine steps in each order. Each negative commutator brush wilithus move from 9 to 0, 0 to 1, and so on to the 8 spot. But,

when a register member moves in a subtract direction from negative 9 indicating position to negative 0 indicating position, the register member is also moving in a subtract direction from positive 0 indicating position to positive 9 indicating position. As explained before, during such movement, lug SI of negative transfer cam 22 is efiective to operate an arm 51 to cause contact arm 45 to engage its contact 49 with contact Consequently, during the transfer period after entry of negative 9999, negative 1 will be carried from each order to the next higher order and from the highest order to the units order. At the end of the carry entry period, the negative commutators will have their brushes engaged with their 9 spots. Further, since contacts 495i of the highest order were closed, the circuit of related magnet II! will be closed upon closure 01 cam contacts in and 124. Accordingly, the negative commutators will be effective during total taking operation, and negative total 9999 will be read out.

Assume, next, that positive 5000 is entered during an entry or card cycle. when the negative registration is 9999, the positive registration is the nines complement; i. e., 0000. The addition of 5000 during the first card cycle moves the register denominations to positive 5000 positions and to negative 4999 positions. Assume that the next entry is positive 4999, At completion of this entry, the register member will be in positive positions 9999 and in negative positions 0000. The negative commutators will still be eifective for total readout operations, so that a total taking operation at this time would cause the true balance 0000 to be read out. Assume a next entry of positive 1. The entry of positive 1 in the units order advances it from positive 9 to positive 0 position and from negative 0 position to negative 9 position. As the units order moves in an addin direction from 9 to 0, additive carry of l is effected to the tens order and, through the long carry contacts 4950 of the tens, hundreds, and thousands order, positive 1 is carried'also .to the hundreds, thousands, and units orders. At the end of this entry and carry' period, the totalizer will be in positive 0001 position. As 1 was carried to the thousands order, its related transfer contacts 49-5i were closed. Hence, upon closure of cam contacts I23 and I24, magnet I26 is energized, causing deenergization of magnet H8, so that the positive commutators will be rendered effective for total readout.

The same principle of. operation is applicable where the highest order of the totalizer is not to be used for receivingentry from the card of any number 1 to 9. Thus, in the totalizer discussed previously in connection with Fig. 7, there were three orders, of which the hundreds order was to be used merely as a negative or positive balance detecting means. Assume entry of maximum positive 99 in such a totalizer. There will be no carry efiected from any order to the next. The positive commutators will be effective and 99 will be read out in a total taking cycle. Assume, in-

stead, that maximum negative entry 99 were made. Then, as the units order moved in a subtract direction from positive 0 position to positive 1 position, carry' contacts 49-5! would be closed. Similarly, carry contacts 49-5i of the tens order would be closed. Accordingly, during the carry period, 1 will be carried in a subtractens to hundreds orders. Further, with the hundreds order initially at 0 position and the totalizer conditioned for subtraction, a notch 60 of negative carry cam 22 will be receiving the projection 58 of arm 51 (Fig. 1) and the arm will be in control of interposer 53. Hence, the contacts 49-50 .of the hundreds order will be closed. Thus, upon entry of negative 99, a long negative carry will be eflected from the hundreds to the units order. 50 At the end of carry operations, the register members will be in positive value positions 900. As the hundreds order moved in a'subtract direction from positive 0 to positive 9 position, contacts 495i were closed. Hence, upon closure 5 of cam contacts 123 and I24, magnet H8 will be energized and the negative commutators selected for readout operation. With the register members in positive 900 positions, the negative registration is 099. As usual, when the highest order is merely a kind of balance detecting order, no

total is taken therefrom. Hence, with the negative commutators of the tens and units order reading 99, this negative balance will be read out during a total taking operation.

The operating circuits for the magnets 89 of the reversing gears are not shown in Figure 10, because each circuit is similar to that shown in Figure '7. As explained each of the four pairs of denominations A, B, C, D, has its own revers- 7 ible gearing and related magnet 89 and associated relay 9'I9la9lb. The two circuitsfor the relay coils 91 of the denominations A and B will both be connected to the single brush of the upper brushes, which reads the subtraction des- 75 ignating hole pertaining to the numbers to be tive direction from units to tens order and from i entered into the totalizer A-B. Similarly the two circuits for the relay coils 91 of the denominations and D will be connected together to the brush which reads the subtraction designating hole pertaining to the numbers to be entered into the totalizer C-D. I

In the arrangement shown the positive commutators are normally efiective and the selecting means operate to cause the negative commutators to become effective, but the reverse arrangement, in which the negative commutators are normally eflective can equally well be used. In such reverse arrangement, it will be understood that the starting position of the totalizer will be negative position 0 which corresponds to positive position 9.

The totaiizer shown and described is arranged to operate on the decimal notation, but it will operate on other notations if the transfer cams have the appropriate number of notches and projections and the locking plates and 23 the appropriate numbers of teeth. Thus, a denomination may be arranged to add and subtract halves (units of ten shillings for example) by providing fifteen notches and projections on the transfer cams instead of three. Oradenomination may be arranged to operate on the duodecimal notation (units of pence for example) by providing the locking plates 20 and 23 with 36 and 24 teeth respectively instead of and 20, the transfer cam having three notches and projections.

- Thereby the magnet 34 may be energised at any of twelve points in a cycle. The indicating wheels or read-out commutators on the register member will be given the appropriate indication, or segments and connections.

In punched cards, however. it is theusual practice to record digits in the duodecimal notation by recording the digits 9 t0 0 in the positions usual in the decimal notation and to record the digits 10 and 11 in two positions at the X and Y points respectively in the cycle. Since these positions follow the 0 position instead of immediately preceding the 9 position, it is customary to read the duodecimal column by upper brushes during a cycle previous to the cycle in which the card is read by the lower brushes and to register the hole read in a pence translator" which emits an impulse to the entry magnet at the proper point in the next cycle. As such translators are well known, their arrangement need not be described.

Alternatively, a duodecimal column may be read and registered in the totalizer without the use of a translator as follows. The register mem- 20 turns through the space of 12 teeth. A convenient arrangement for this is shown in Figure 12, which, by comparison with'l 'lglire 2, shows the modifications n. 'Ihe locking plate 2lisloooeonthesleeve l6 andisfixedtoa wheel I33 of 40 teeth which engages a pinion I34 pivoted on a bracket I35 fixed to the plate I. The shaft I3 is ccentric in the sleeve i6 and carries a wheel I33 of 48 teeth and the two transfer cams 2| and 22. The wheel I36 engages the pinion I34, ihe eccentricity of the shaft I! being made equal to the difla'ence between the radii of the wheels I33 and I33. Thereby shown in Figure 13.

transfer cams and. shaft II are geared to the lockingpiate 23 in the ratio 10 to 12.

The digits from 9 to 0 are entered into the denomination by energising the magnet 34 at the appropriate points in the cycle as in a decimal denomination. The digits l0 and 11 are entered by energising the magnet at the G and 1" points respectively, that is, at one and twopoints respectively before the 9 point. These positions are read by the upper brushes and the energising of the magnet 34 is controlled by the circuits These circuits are additional to those shown in Figure 7 and are shown applied to the units denomination; the circuits of Figure 7' are not therefore repeated in full in Figure 13. The upper brush of the brushes UB which reads the duodecimal column is connected to contacts I54.

closes at X, so that if the said upper brush makes contact at an)! hole indicating a digit 10, the circuit through relays I33 and I3! is complete. The relay I33 closes its contacts I381: to establish a holding circuit through relay I33 after the hole has passed the brush, such circuit extending from line 96a via the holding contacts Illa, relay- I39, relay I3I, relay contacts Bid and cam The auxiliary contacts 3b are also closed during this time in circuit with the cam contacts I43 and contacts 95a of the units order entry magnet 34. Cam contact I43 closes at G in the cycle which isl index point ahead of 9 in the following cycle and thereby enters the value 10. In the parallel circuit cam contact I42 closes at Y to energlse relay l 4| in the event of a hole being present at the 11th or Y index point on the card, the circuit being maintained by relay contacts l4la, relay coil i4i, relay I33, relay contacts i38a and cam contact I54. Cam contact I44 closes at F in the cycle 2 index points head of 9 in the following cycle and completes the circuit through the closed contacts i4lb, contacts 85a and the units order entry magnet 34, thereby entering the value 11. Provision is made to prevent similar entries being made in other denominations by the opening of contacts 'l3lb sequent upon either a10 or 11 hole being present in the column. Other values 9 to 0 can thus be sensed by the lower brush and effect energisation of the units order entry magnet 34 through the normally closed contacts I381) at the appropriate times. V

The register member may be controlled in other ways than by the magnet 34 with cams 3|, 32 and 34. For example, the cams may be dispensed with by the arrangement shown in Figure 14. I

This figure shows the modifications to be introduced into the arrangement of Fi ure 1, parts remaining without modification not being shown,

.- excepting the locking plate 28 and the locking magnet [45 ceases to be energised, a spring I4! returns the lever 24, 28 into the podtion shown inwhich the registermemberislockedbythe plate 25.. The register member then turns during the period in which the magnet I45 is energised, and the number read from a punched card can be entered into the register member by keeping the magnet energised from the point in the cycle at which the digit recorded is read until point 0 in the cycle. Similarly, carry value 1 can be entered by energising the magnet I45 for a period equal to the interval between two successive points in the cycle and this may be effected by causing the transfer cam I21 (Figure '7) to close its contacts for this period. The arm 44 of the lever which latches the transfer arms may be unlatched by means of the magnet I48, which, when energised, attracts the armature I49 on the other. arm I50 of the lever 44, III,'into the pomtion shown. The lever 44, I50 is springpressed counter-clockwise by the spring I5l. The magnet I48 may be included in the circuit of cam contact 99, as shown in dotted lines in Figure '7. The modification in the circuits of Figure 7 required to energise the entry control magnet for the period representing the digit read is shown in Figure 15. The lines 94, instead of running directly from the lower brushes Lli'to the contacts 95a of the entry control magnets 34, as in Fig. 'I, pass through relays I52 to entry agnets such as I45, one of which-is shown in Fig. 15. These relays have holding contacts I52a which maintain the circuit from line 96, cam contact I53, contacts l52a, relay I52, wire 94, contacts 550, entry control magnet I45 to line 96a. This circuit is broken at point. 0 by the cam contact I53.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to the illustrated structures, it will be understood that various omissions and substitutions and changes in the form and'details of the structures illustrated and in their operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In combination, denominational orders of register members, gearing to move the members in one direction to add and in the opposite direction to subtract values, a common entry control magnet for governing the extent of such movement of a member in either direction, means to selectively "govern the direction in which said gearing moves said members, a circuit for energizing the magnet to cause the related member to receive a carry entry movement from the gearin switch means in said circuit, a pair of alternatively effective transfer devices operated by the preceding order member to close the switch means, and means controlled by the gearing, in accordance with the direction of movement of the members affected thereby, for selectively rendering one of said devices effective and the other ineffective, whereby one of the devices will be effective during adding operation and the other will be effective during subtracting operation.

2. In combination, a denominational order register member, means to actuate the member in ascending direction during addition and in descending direction during subtraction, said member including an adding transfer cam and a sub-- traction transfer cam, a single transfer switch, means for operating said switch under control of either cam and including selectively shiftable interponent means for placing the switch under control of either cam, means for selectively 'shifting the interponent means to place the switch either under control of the adding transfer cam to be operated thereby as the register member moves during addition to a predetermined positive value position or under control of the subtraction transfer cam to be operated thereby asthe register member during subtraction moves to a predetermined negative value position, transfer eifecting means to effect a transfer from said order register member to another order register member, and a circuit eifective under control of said switch for bri g aboutoperatlon of the transfer effecting means.

3. In a machine having denominational order register members, including the highest order member, movable variable, difierential extents in positive direction or in opposite, negative direction to receive entries of positive or negative values, respectively, and having carry contacts closed by the highest order member to .control carry to the units order member as the highest order member during variable, differential entry receiving movement in either direction traverses a critical position, the combination of positive and negative value readout commutators for each order register member to respectively register true positive and negative balances, a common emitter having direct wiring to the positive commutators and complementary wiring to the negativ commutators of all the orders, a readout circuit for each order closed through said emitter and having alternative switching connections to 1 be adjusted into circuit either with the negative or the positive commutator of the order, adjusting means for adjusting the switching connections of the orders to shift said connections from the readout commutators pertaining to one sign balance to the readout commutators pertaining to the opposite sign balance, means under control of said carry contacts, when closed, to operate said adjusting means,-and means for maintaining the adjusting means in operation after reopening of the carry contacts.

4. In a machine having ,a totalizer provided with denominational order register members, including the highest order member, movable variable, differential extents in positive direction or in opposite, negative direction to receive entries of positive or negative values, respectively, and having carry contacts closed under control of the highest order member to control carry to the units order member as the highest order member during variable entry receiving movement in either direction traverses a'critical position, the combination of positive and negative electrical, value readout members in each order connected for common movement and complementarily wired to one another, a readout circuit for each order having alternative switching connections to the positive and negative readout members, relay means for shifting the switching connections from the readout members pertaining to one sign balance to the readout members pertaining to the opposite sign balance, a circuit for operating said relay means, said circuit including said carry contacts, means for completing said circuit after the carry contacts have closed upon the highest order register member traversing the critical position while moving to receive an entry of a value of one sign,- a, holding circuit for the relay means closed after said carry contacts have reopened, and means for breaking the holding circuit when the carry switch is again closed during movement of the highest order register member through said critical position when receiving entry of a value of the opposite sign.

5. In a machine having a totalizer provided with denominational order register members, including the highest order member, movable variable, differential extents in positive direction or in opposite, negative direction to receive entries of positive or negative values, respectively, and having carry contacts closed under control of the highest order member to control carry to the units order member as the highest order member during variable entry receiving movement in either direction traverse a critical position, the combination of positive and negative electrical, value readout members in each order connected for common movement and wired complementarily to one another, a readout circuit for each order having alternative switching connections to the positive and negative readout members, means for shifting the switching connections from either the positive to the negative readout members or vice versa, a stepping device for rendering said .shifting means eiTective to shift the switching connections in one direction and then in the opposite direction upon successive steps of actuation oi the device, a magnet operating upon each energization'thereof to eifect a step of actuation of the stepping device, and a circuit closed under control of said carry contacts each time the highest order member traverses the critical position, while receiving an entry, for momentarily energizing said magnet.

6. In a machine having a totalizer with denominational order register members, including the highest order member, movable variable, differential extents in one direction to receive positive value entries and in opposite direction to receive negative value entries and of which the highest order member passes in one direction through a critical position upon change in the totalizer balance from one sign to the opposite sign and passes in the opposite direction through the critical position upon change in the totalizer balance from the opposite sign to the previous sign; the combination of readout circuits for reading out the true figures of a negative balance in the totalizer, alternative readout circuits for reading out the true figures of a positive balance in the totalizer, means for switching from the readout circuits for one sign balance to the readout circuits for the opposite sign balance, contacts closed by the highest order register member upon passing in either direction through the critical osition, and electrical means alternately .HAROLD HALL KEEN.

THOMAS OLIVER WRIGHT. 

